Two basic problems that are addressed during a patient's routine visit to a dentist are plaque and tartar (also called calculus). (The term “dentist” for purposes of this application includes a doctor of dental surgery, a periodontist, a dental hygienist, a dental assistant, a veterinarian, a veterinary dentist, a veterinary assistant, or any other person who treats teeth for plaque, tartar, or related problems. The term “patient” means a being with teeth, and includes humans and non-humans, including but not limited to dogs, horses, or other animals who need dental treatment.)
Plaque is a sticky biofilm while tartar is a crusty deposit. Removal of plaque and tartar usually involves one or both of two elementary procedures for cleaning the patient's teeth. A dentist will scale the teeth by mechanically removing plaque which has formed as calculus on the surface of the teeth. Scaling can be done using hand tools or power scaling tools. Polishing is the removal of plaque and the smoothing of the surfaces of the teeth to make it difficult for plaque to attach. Polishing is usually done after scaling but can be done first if the dentist chooses. Polishing is conventionally accomplished by use of a prophy angle, a dental device which has a rotating rubber cup at the end of a dental handpiece, a motorized tool. The dentist uses the prophy angle to apply a prophy paste to clean and polish the tooth surfaces mechanically.
A prophy angle as is known in the prior art has three sections attached in this order: a neck section, a grip section, and a drive section. The motor or turbine on a dental handpiece attaches to the drive shaft of the prophy angle, which extends axially from the drive section through the grip section and into the neck section. As the dental handpiece is activated, it turns the drive shaft and a driving gear at its forward end inside the neck section. The driving gear interacts with a driven gear located in the neck section. The driven gear rotates the prophy cup. The motor or turbine need power and accordingly have a cord attached to the near end of the drive section, the cord either conveying electricity to the motor or compressed air to the turbine. In some cases, the tool is cordless and contains a battery to power the motor.
The dentist polishes the patient's teeth by dipping the prophy cup into a container of polishing paste and applying the paste to the patient's teeth. The rotation of the prophy cup polishes the teeth, but also tends to splatter the paste. One prior-art solution was the use of vanes or ribs within the prophy cup, as described in U.S. Pat. No. 4,929,180 to Moreschini, Stay Full-Easy Load “Turbo” Prophylactic Polishing Cup and in United States Published Patent Application No. 2008/0076091 to Moreschini, ‘Turbo’ prophy cup with step like prophy paste collecting reservoirs on turbine like vanes.
Another prior-art solution was to use a wiper to remove slurry as the prophy cup rotates, as described in, for example, U.S. Pat. No. 8,784,102 to Kumar, Prophy Cup for Dental Handpiece.
To manufacture a wiper as known in, for example, the '102 Patent to Kumar, the body of the prophy angle is manufactured in two parts, with a recessed channel in the neck section of the body. The wiper is manufactured separately and is constrained within the recessed channel to position the wiper properly with respect to the prophy cup. The two body parts are then assembled with the gears to create a functioning prophy angle.
Accordingly, to add a wiper to an existing design of a prophy angle, the entire prophy angle must be redesigned. The use of a recessed channel to hold the wiper requires a re-assessment of the space within the neck section, as existing prophy angle designs do not have the recessed channel. Accordingly, to add a wiper to a prophy angle, there must be a redesign of the molds for the two body parts, a redesign of the molds for the driving gear and the driven gear, and a new mold for the wiper. This method is particularly expensive because new molds for high-volume production are costly. A need exists, then, for a method of manufacture of dental appliances and parts that avoids the costs of the prior art.